Electric welding-machine.



I., M. SPARKES.

ELECTRIC WELDING MACHINE.

APPLICATION FILED JAN. I7 I9I6.

Patented June 5, 1917.-

3 SHEETS-SHEET I.

INI/PINTOR. Ja/m/Lw/Q/f'. MUAH A TTORNE I I. IVI. SPARKES.

ELECTRIC WELDING MACHINE.

APPucATloN FILED JAN. 11. 1916.`

Patented June 5, 1917' 3 SHEETS-SHEET 2.

A TTORNE Y.

I. IW. SPARKES.

ELECTRIC WELDING MACHINE.

APPLIcATloN FILED 1AN.17,1916.

' Patented June 5,1917.

3 SHEETS-SHEET 3- lnvemor.

UNITED STATES PATENT FFICE.

JAMES IVI. SPARKES, OFPEABODY, MASSACHUSETTS.

ELECTRIC WELDING-MACHIN E.

,flow rst through one of two articles` to be welded together, thereby to pre-heat the same, and then through both of the articles when they are brought in contact, thereby to make the weld, and one of the objects of my invention is to provide a device which is automatic in its action and in which the connections will' be automatically made to direct the current through one of the articles only when said articles are spaced apart,

and to direct the current through both articles when the articles are brought in contact. Another object of my invention is to provide a novel construction whereby during the pre-heating operation the current will beco'nfined to the particular portion of the article which is to be pre-heated, thus enabling said article to be pre-heated with a minimum consumption of current. Other objects of my invention are to improve single-transformerA electric-welding apparatus, all as will be more fully hereinafter set forth.

In order to give an' understanding of my invention I have illustrated in the drawin s a selected embodiment thereof which wiIl'now be described, after which the novel features will be pointed out in the appended claims. v

In the drawings, Figure 1 is a side view of a welding machine embodying my invention;

Fig. 2 is a top plan view of Fig. 1 with` one of the work clamps removed;

Fig. 3 is a section on substantially the line 8-13, Fig. 1, looking toward the right;

Fig. 4 is a'perspective view of one of the electrodes; Figs. 5, 6 and 7 illustrate different welds which can be made with my machine;

Patented June 5, 1917.

Application :filed January 17, 1916. Serial No. 72,383. i

Fig. 8 is a fragmentary side view of the device for varying the resistance in the secondary or working circuitof the transformer;

Fig. 9 is a view showing a form of electrode adapted for use in welding round tubes or bars.

The machine herein illustrated is especially designed for welding the end of a rod, bar, or tube against the side of another rod, bar, or tube thus making a T-j oint. The rods, bars or-tubes may have any exterior contour, and as illustrating some varieties of work, I would refer to Figs. 5, 6 and 7 Fig. 5 shows the end of the relatively small round solid rod 1 welded to the side of a larger round solid rod 2, the weld being indicated at 3. Fig. 6 shows the end of a round tube 4 welded to the side of a larger tube 5, the weld being indicated at 6, and Fig. f7y shows the end of a square tube`8 welded to the side of a larger square tube 9, the weld being indicated at 10.

In carrying out my invention I provide ,I

two work-receiving electrodes which are movable toward and from each other and to which the two pieces of work to be welded together are clamped, and I also provide automatic means by which, when the electrodes are so positioned relative to each other as to hold the articles separated from each other, the current will be directed through one of the articles only and preferably through that portion of the article where the weld is to be made, thereby to preheat said article, and when the velectrodes are moved together to bring the two articles into contact, connections will automatically be made by which the current is directed through both articles thereby forming the weld. The two work-receiving electrodes are designated 13 and 38, respectively, the electrode 13 being mounted on a support 21 which in turn is carried byy but insulated from a table or base 23 and the electrode 38 being carried by a support 39 which in turn is secured to but insulated from the base 23.

The two'articlesto be welded together are indicated at 11 and 12, respectively, and themachine herein shown is especially designed for welding the end 92 of the article 11to the side 91 of the article 12. The supports 21 and 39 are movable relative to each other, as will be presently described. i

The work-receiving electrode 13 is provided ywith two work-engaging or contactv faces 16 and 17 against which the side of the article 12 yis clamped, said faces being formed on two upwardly-directed extensions 14 and 15. These contact faces and eXtensions 14 and 15 are insulated, from each other, this being herein provided for by I ,cross-section, as shown in Figs. 1 and 2,

these faces will be flat faces. In Fig. 9 I have shown an embodiment of the invention where the-contact faces areg curved to fit a round bar or tube.

The article 12 is'clamped against the contact faces 16, 17 by means of an insulated' clamping jaw 2,5 and Iwill also preferably insulate the under side ofthe article 12from the portion of the electrode on which it rests so that said'article' will have electrical. contact with the electrode through the contact lfaces 16, -17 only. The reason for this will be presently described.

VAny suitable mechanism may be employed for operating the clamping jaw 25. As herein shown said jaw is secured to but insulated, by means of insulation 105, from a block 104 which isA cor iected by a link 26 to the head 27 of anoperating lever 28, said lever having a slot 29 therein, through which extends a pivotal pin or screw 30. The head 27 has connected thereto a link 31 which is pivoted at 32 toa block 33, that is adjustable on the support 21:. With this construction, the movement of the lever 28 to the left,- Fig. 2, will withdraw the clamp from engagement with the article 12, while the movement to the'right will bring the jaw 25 into clamping engagement with the article 12. The block 33 is made adjustable so as to accommodate articles 12 of different sizes. This adjustment may be provided for in various ways. As herein shown the -block 33 is pro-vided with slots 34 in which operate guiding pins 35 carried by the support 21. '36 designates an adjusting screw which screws into the support 21 and is` swiveled into a lug 37 formed on the block 33. The turning movement of the adjusting screw 36 will adjust the block 33 on the support 31.

The relatively small article 11 is supported on the electrodeor terminal member l38, which is in turn carried by a support or vblock or head42 carrying the work-clamping device. This Work-clamping device is in the nature of a clamping member 43 which is adapted'to be moved into and out of contactA with the article 11 by an operating lever 44 which is connected to the block 42 and to a clamping member 43 by the links 454 and 46, respectively, :this construction bcv' ing similar tol that described foroperating the clamp .25. The clamping member 43 is shown as formed on the end of a lever 47 which is pivoted at 48 to lan arm 49. The arm 49 is shown as provided with a slot 50 inl which the pivotal pin k51 for the lever 47-k operates, and said lever has a screwthreaded stud 52 extending upwardly the'refrom through the flange 53 formed on the arm 49,- a nut 54 being screw-threaded on the stud .tov adjust and hold the end of the lever in its adjusted position.

The block or head 42 is adjustably mounted on the arm 41 so as to provide for effectively clamping articles 11 of different sizes.l The adjustment of the block 42 is provided for by an adjusting screw 55 which is swiveled in an ear 56 formed on the block and has screw-threaded engagement with the bracket 41. 57 are guiding screws carried by the bracket 41 and operating in slots v58 formed in the head 42 for guiding it as it is adjusted.

- yThe supports 39 and 214 are constructed to j be moved relative to each other so as to bring the two articles 11 and 12 into contact when the weld is to be' made. This relative movement might b secured by moving either one of these parts, but in the construction illustrated the support 21 is that which is moved, and`for giving the desired movement to said support, I have provided an operating lever 59 having a head 6 0 at one end which is connected by' a link 61 with a bracket or extension 62 formed on the table 23 and is also connected by a link 63 with the slide 21. Turning movement 'of the lever 59 to the right, Fig. 2, will move the support 21 for- 80 indicates the secondary circuit of the transformer 106, said circuit being referred to as the working circuit. One end of this circuit is Connected to the support 39 and the other to the support 21. Said circuit is illustrated as having a switch 99 therein by which it may be opened or closed.

As stated above, in welding the end of a rod or tube 11 to the side of a larger rod or tube 12, it is necessary to pre-heat the part of the rod or tube 12 where the weld is to be made. In my invention I accomplish this pre-heating by connecting the electrode section 18 andthe electrode 13 in series in the working or secondary circuit of the transformer when the articles are separatedfrom each other, so that the current will pass from the Contact face 17 to the contact face 16 through the article 12 only. By reason ofthe fact that the article 12 is insulated from the portion 20 of the electrode 13 by insulation 107, and the jaw isinsulated from the head 104 by insulation 105, the current which passes from the contactface 17 to contact face 16 will be confined to the face 91 of the article 12, and thus only the portion of the article where the weld is to occur will be pre-heated. When the pre-heating is accomplished and thearticles 11 and 12 are brought into contact for the welding operation, the two sections of the electrode 13 are connected in parallel so that the welding current will pass from the article 11 to the pre-heated portion ofthe article 12 and thus to both of the contact faces 16 and 17 This produces an even uniform welding heat over the entire surface or area to be welded. The means I have herein provided for accomplishing this comprises a contact member 64 pivotally mounted at 65 on the electrode section 18 and provided at one end v with a contact 66 adapted to engage a contact 67 formed on the slide 21 and provided at the other end with a contact 68 adapted to engage a contact 69 formed on a block 70 which is secured. to the support 39 but is insulated from the electrode 38 by insulation 71. The contact member 64 is so constructed that when the contacts 68 and 69 are in engagement the contacts 66 and 67 are separated from each other, as shown in Fig. 2. Means are also provided for holding the contacts 68 and 69 in engagement when the carrier 21 is'retracted, thereby electrically connecting the electrode 1section 18 with the support 39 and for bringing the contacts 66 and 67 into engagement when the carrier 21 is moved forwardly, thereby electrically Connecting the electrode section 18 with the carrier 21. To accomplish this I have provided the following means: 81. and 82 are two yieldingly mounted ported in the head 83-of a bracket 84 that is secured to the table 23. The contact mempins that are supber 64 is provided at each end with a head 86 having an inclined face 87 and said heads 86 have such a position relative to the pushpins 81 and 82 that when the carrier 21 is retracted, the pin 82 will engage the head 86 at the right hand end of the member 64, thus holding the contacts 68 and 69 in engagement, as shown in'F ig. 2, while when the carrier 21 is moved forwardly, the righthand head 86 will be carried out of engagement with the pin 82 and the pin 81 will wipe over the contact face 87 at the lefthand end of the member 64 and will pass on to the left-hand headI 86, thus swinging said member 64 into a position to bring the contacts 66 and 67 into engagement. In the operation of the device the carrier 21 will be retracted and the two articles 11 and 12 will be clamped to their respective electrodes, the article 11 being so positioned that it will be separated from the article 12 when the carrier 21 is retracted, but will be brought into engagement with said article 12 when the carrier 21 is moved forwardly. After the two articles 11 and 12 have been properly clamped in position, the transformer circuit 80 is closed by a, suitable switch 90. It will be noted that when the I' support 21 is retracted, the contacts 68 and ythe lever 59 is operated to move the support 21 forwardly to bring the end 92 of the article 11 against the pre-heated portion 91 of the article 12. During this movement the contact member 64 is turned by the pin 81, so as to bring the contacts 66 and 67 into engagement, thus electrically connecting the electrode section 18 with the electrode 13. As soon as the two articles 11 and 12 are brought into engagement the current will iiow from the support 39 through the electrode 38 and article 11- to the pre-heated portion 91 of the article 12 and thence to the carrier 21 through both of the faces 16 and 17. rlhe welding heat is thus evenly distributed, and an even and perfect weld will be formed.

It will thus be seen that I have provided a device in which the electrode section 18 is'electrically connected to the support 39 during the pre-heating operation and is electrically connected to the carrier 21 during the welding operation. In other words the contact face 17 is arranged in series with the contact face 16 during the pre-heating operation and is connected in parallel with pivoted to the support at 100 and having a shoe 94 adapted to move over the edges of the contact plates 97, ,98. This arm is guided by a pin 101 extending therefrom and operating in a slot 102 in a guide plate 103.

When the arm is in `its lowest position, the.

, current has to pass through all ofthe plates 97, 98, thus giving a maximum resistance. As the arm is swung upwardly certain of the plates are cutout of the circuit, thus reducing the resistance. i.

It will thus be seen that the operation of directing the current through the article 12 only to pre-heat the latter when the two articles are separated, and for directing 'the current through both articles when they are brought into contact, is accomplished automatically and by the movement of the elec trode 13 toward and from the electrode 38.

INo separate hand manipulation is, therefore, required to switch the current from one article to both articles. The advantage of the construction wherein the article 12 is insulated from its supporting electrode, eX- cept where it contacts with the faces 16 and 17 is that the current is confined to the face 91 to be heated and no current is wasted in 'heating the part of the article 12 where noweld is to be made. My invention, therefore, includes a construction by which the preheated current is localized at Athe pointto be pre-heated.

In Fig. 9 I have illustrated a form of electrode especially designed for use in holding a round tube or bar. In this construction the electrode is designated 130 and the insulated section by 180 andthe two curved contact faces by 160 and 170, respectively. In order to localize the current at the point where the weld is to be made, I have shown a filling piece 108 inserted between the eXtensions 140 and 150 and insulated therefrom, said filling piece having such a shape as to cause the current to flow through the round article 120 to be pre-heated at substantially the diametrical line of the weld. Without this filling piece, the current would tend to follow the shortest course from one contact face to the other and would thus pass largely around the lower portion of the surface to be pre-heated.

- The bracket 84 is adjustably mounted on the table 23 so that it can be adjusted longitudinally of the table, this being accomplished by forming the foot of the bracket with slots 111 therein in which are received the clamping screws 112. By adjusting the bracket 84 to the right, Fig. 2, the pins 81 and 82 will be so positioned that the pin 82 will always remain in contact with the righthand head 86, and thus the contact member 64 will be maintained in contact with the block in both positions of the electrode 13. Where this adjustment is made and the two articles are brought into contact, a por tion ofthe working current will flow from the support 39, through the block 70 contact member 64 to the contact. face 17 and thence through the article 12 to the contact face 16, and the rest of the current will iow through the electrode 38 and article 11 to the article 12. With this varrangement the portion 91 of the article 12 will receive more current than the end 92 of the article 11, and will thus become heated more rapidly.

When this adjustment is made it is possible point 91 of the article 12 by reason of they fact that this portion receives more current ythan the article 11.

While I have illustrated some selected embodiments of my invention, I do not wish to be -limited to the constructional features shown.'

I claim:

1. In an electric-welding machine, the combination with two work holding elements, one of which has two separated work` engaging faces adapted to engage one of the two pieces to be welded together at each side of the place where the weld is to be made, of means to move said elements' relative to each other to bring the two pieces into contact, means operative automatically when the two elements are in a position to hold the two pieces separated from each other to connect said two faces to a source of current supply in series with each other whereby said lirstnamed piece is preheated at the place to be welded and to connect said faces in parallel with each other and in series with the other work-holding element when said elements are in a position to hold the pieces of work in contact.

' 2. In an electric-welding machine, the combination with two work-holding electrodes, one of which presents an insulated section and two worlcengaging faces, one of said faces being on said insulated section, of means connecting said electrodes to a working circuit,'means to give said electrodes a relative movement toward and from each other, and means electrically connecting said insulated section to one electrode when the electrodes are in one position relative to each other'and to the other electrode when said electrodes are in another position relative to each other.

3. The combination with two work-holding electrodes, one of which has an insulated section provided with a worlcengaging face, of means for moving said electrodes toward and from each other, a working circuit connected to said electrodes, a swinging contact member carried by said insulated section,

and means to establish an electrical contact between said contact member and one electrode when said electrodes are in one position relative to each other and between said contact member and the other electrode when the electrodes are in another position relative to each other. i

4. The combination with two work-holdingelectrodes, one of which has an insulated section provided with a work-engaging face, of means for moving said electrodes toward and from each other, a working circuit connected to said electrodes, a swinging contact member carried by said insulated section, and means to establish an electrical contact between said contact member and the other electrode when said electrodes are separated from each other and between said contact member and the firstnamed electrode when the electrodes are in position to bring the two pieces to be welded into contact with each other.

5.y In an electric-welding machine, the combination with two work-holding electrodes, of a transformer having its secondary connectedto said electrodes, means to move said electrodes relative to each other to bring two articles held thereby into welding contact, and automatic means to cause the cur rent in the secondary of said transformer to ow through one of said articles only when the electrodes are in a position to hold said articles separated and to cause said current to flow through both articles when said electrodes are moved into a position in which the electrodes are in welding contact.

6. In an electric-welding machine, the combination with two work-holding electrodes, of a transformer having a secondary connected to said electrodes, means to move said electrodesl relative to each other to bring two articles held thereby into welding contact, and `means rendered operative by such relative movement to cause the current in the secondary of said transformer to How through one of the articles only when the electrodes are in a position to holdv said articles separated and to cause said currenttc flow through both articles, when said electrodes are moved into a position in which the electrodes are in contact.

7 .In an electric-weldmg machine, the combination with two work-holding electrodes, of a transformer having its secondary' connected to said electrodes, means to move said electrodes relative to each other to bring two articles held thereby into welding contact, mechanism operative to cause the current in said secondary of said transformer to flow through one of the articles only when said articles are spaced from each other and through both articles when the articles are in contact, and means operative when ithe current is flowing through the first-named article only to confine the current to the portion of said article that is to be pre-heated.

8. In an electric-welding machine, the combination with two work-holding electrodes, engaging facesy insulated from each other and against which one of the articles to be welded is placed, means to move said electrodes relative to each other to bring two articles held thereby into welding contact, a secondary having its transformer connected to said electrodes, and mechanism operative to cause the current from said secondary to flow from one Contact face to the other through the article engaging said faces when said articles are separated from each other and to flow through both articles when the articles are in welding contact.

9. ln an electric-welding machinethe combination with two work-holding electrodes, one of which has two separated workengaging faces insulated from each other and against which one of the articles to be welded is placed, means to move said electrodes relative to each other to bring two articles held thereby into welding contact, a secondary having its transformer connected to said electrodes, mechanism operative to cause `the current from said secondary "to flow from one contact face to the other through the article engaging said faces when said articles are separated from each other and to flow through both/articles when the articles are in welding contact, and means insulating the first-named article from its electrode at the points eXcept where it contacts with the contact faces whereby the current flowing through said article is confined to the portion where the weldis to be made;

10. ln an electric-welding machine, the combination with two work-holding electrodesgof two supports on which said electrodes are sustained, means to move said supports relative to eachother to bring two articles carried by the electrodes into welding contact, a transformer having its secondary connected to said supports, one'of said electrodes having a laminated structure and a contact arm connected to the support for said electrode and adapted to be moved into contact with the different laminations of said electrode thereby to vary the resistance in the circuit.

one of which has two separated workll.. 'In an electric-welding lnaehille, the

. head to said jaw, and another link connecting said head to said member.

l2. In an electric-Welding machine, the

` combination with a Work-supporting member, of a Work-.clamping jaW for clamping the Work thereagainst, an actuating -lever having a slotted head, a in carried by said member and extending t rough the slot of the lever, a link connecting one end of said 'head to said jaw, another link connecting the other end of said head to said member,

said pin being in line with the pivotal connection between said links and said head.

13. In an electric-Welding machine, the combination with a Work-suporting member, of a clamping jaw for clamping the member thereagainst, and jawactuating mechanism comprising a lever having a slotted head, a fulcrum pin fixed with relation to the Work-supporting memebr and extending through the slot of said head, a link connecting said head to said jaw, and another point fixed with 30.

ivoted at one end to a relatlon to the Work-supportmg member and at the other end to said head.

In testimony whereof, I have signed my name to this specification.

' JAMES M. SPARKES. 

